Optical cable and method for manufacturing thereof

Abstract

An optical cable comprises at least one bundle composed of a plurality of light waveguides which are preferably wrapped as a layer on a cable core. A non-hardenable filling compound is provided on the inside region of the light waveguide bundle between the layer of waveguides and core and the outer surfaces of the layer of optical waveguides is coated with a hardenable compound.

We claim: 
     
       1. An optical cable having at least one bundle of a plurality of optical waveguides being arranged in a core of said cable, said plurality of optical waveguides forming outer gores and inner gores, a non-hardening filler compound being disposed in the inner gores and a hardenable compound being applied only in the outer gores of the bundle. 
     
     
       2. An optical cable according to claim 1, wherein the hardenable compound forms an outside skin holding the optical waveguides of the bundle together. 
     
     
       3. An optical cable according to claim 1, wherein at least the inner gores of the optical waveguides bundles are completely filled by the non-hardening filler compound. 
     
     
       4. An optical cable according to claim 1, wherein the hardenable compound is composed of a resin. 
     
     
       5. An optical cable according to claim 4, wherein the non-hardening filler compound is composed of a thixotropic material. 
     
     
       6. An optical cable according to claim 1, wherein the optical waveguides of the bundle are stranded with one another. 
     
     
       7. An optical cable according to claim 6, wherein the bundle has a central tensile element and said optical waveguides are standard onto said central element. 
     
     
       8. An optical cable according to claim 7, wherein the waveguides are stranded with an alternating directions of lay. 
     
     
       9. An optical cable according to claim 6, wherein the waveguides are stranded with an alternating lay direction. 
     
     
       10. An optical cable according to claim 1, wherein the hardenable compound at least partially fills outwardly extending gores of the bundle. 
     
     
       11. An optical cable according to claim 1, wherein the bundle includes a central element with the non-hardening filler compound disposed between the central element and a layer of the waveguides and the hardenable compound being disposed on an outer surface of the layer of waveguides. 
     
     
       12. An optical cable according to claim 11, wherein the hardenable compound is composed of an ultraviolet reactive resin. 
     
     
       13. An optical cable according to claim 12, wherein the non-hardening filler compound is composed of a thixotropic material. 
     
     
       14. An optical cable according to claim 1, wherein the non-hardening filler compound is composed of a thixotropic material. 
     
     
       15. An optical cable according to claim 1, wherein the hardenable compound is composed of an ultraviolet reactive resin. 
     
     
       16. A method for manufacturing a cable having at least one bundle with a layer of optical waveguides disposed around a core region, said layer forming outer gores and inner gores between adjacent waveguides, said method including the steps of applying a non-hardening filler compound to the inner gores of the layer of optical waveguides and subsequently applying a hardenable compound on the outside of said layer of waveguides to fill the outer gores. 
     
     
       17. A method according to claim 16, which includes providing a central element in the core region of the bundle, applying a non-hardening filler compound to the central element, subsequently stranding the layer of optical waveguides onto the central element and then coating the layer of stranded waveguides. 
     
     
       18. A method according to claim 17, wherein the step of stranding the waveguides onto the central element having the non-hardening filler compound comprises conducting the central element with the non-hardening filler compound through an interior of a pipe store stranding means which strands the optical waveguides onto the coated central element, and the step of applying the hardening compound applies the hardening compound at the output of the pipe store stranding means. 
     
     
       19. A method according to claim 17, wherein the step of applying the hardenable compound includes confining the hardenable compound on the stranded layer of waveguides and radiating the layer to cure the hardenable compound. 
     
     
       20. A method according to claim 19, wherein the hardenable resin is reactive to ultraviolet radiation and said step of applying a radiation applies ultraviolet radiation to cure the hardenable resin.